Telephone system with automatic ringing.



R. I. UTTER. TELEPHONBSYSTEM WITH AUTOMATIG RINGIIG..

Patented 001;. 6, 1914.

APPLICATION FILED 0UT.25, 1913.

srafrns Para rarer..

RICHARD I. U'I'TER, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITCEBOARD AN'D SPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

To ZZZ 'io/1021i it may concern Be it known that I. RICHARD I. Urrnn, a citizen ot' the United States of America, residing in Chicago, county of Cook, and State ovf Illinois. have invented certain new and useful Improvements in Telephone Systems with Automatic Ringing, ot' which the following is a specification.

My invention relates in general to telephone systems and has to do more part1cularly with automatic ringing systems adapted tor use with operators cord or link circuits, an object ot my invention being to provide an improved and simplified circuit arrangement embodying certain features as will be hereinafter more particularly pointed out in the following specification and claims.

In the accompanying drawing I have illustrated a preferred embodiment ot' my invention which comprises calling and called substations A and .Il connected to centrally located line circuits L and IR respectively adapted to be connected by means of an operators cord or link circuit l). Although but two telephone lines' are shown it is to be understood that there are al number of such lines provided and also a plurality of cord circuits for interconnecting them.

I have preferably embodied my invention in a so-called three-cond1wtor or three-wire multiple circuit and therefore the line circuits L comprisethree-contact jacks J, a line relay LR and cut-oil' relay C() also being provided. The subs-tations A may be of any common battery type and I have shown thewell-known Kellogg form ot' substation. The line circuit Ll is similar to that of- L. the parts thereot` being indicated by reference characters corresponding to the reference characters ot' the line circuit L.

The operators link circuit B includes the usual answering terminal l and calling terminal i2 connected by the heavily marked `tip and sleeve conductors having interposed -condensers 3, l. The third Contact of the answering plug l is connected to battery so' as to provide an energizing circuit. for the cut-oli relay CO of the calling line. but at the calling terminal 2, I have preferably connected the third contact through a switching relay SW to battery whereby said relay anc the cut-ottA relay CO1 ot the called line are energized over the connected series circuit. It the answering end oi' the cord Specification of Letters Patent.

Application ined october 25, 191e.

Iatented Oct. i914. Serial No. 797,154.

circuit I provide an answering supervisory relay AS preferably connected in bridge of the tip and sleeve conductors and arranged to automatically connect the operators telephone O in bridge ot' the cord circuit when a call is answered. Upon extending the calling line to a called line, the switching relay SI'V is energized to automatically disconneet the operators telephone O.

In connection with the calling end of the cord circuit I provide a calling supervisory relay CS and a ringing generator G which are adapted to be alternately connected in bridge ot' the called line through contacts of an interrupter relay IR, which relay IR is periodically energized over a circuit including an .interrupter I. A. ringing control relay IC is also provided which relay serves to control the application ot' ringing current by interrupter relay IR, also serving as a closing relay to close the tip and sleeve talking conductors of the cord, when the called subscriber responds.

`Relays RC and IR are adapted to be energized by a circuit including the battery segment of the interrupter I which interrupter is arranged to alternately connect battery to the ringing control brush C or the interrupter brush R, with a dead period between each alternate connection. That is, after the battery segment leaves one brush there is a short period before it connectsy with the opposite brush. One otl the reasons for this dead period is to prevent an incidental kick of the armature of the calling supervisory relay ("5 from a ringing current discharge. to ettect a premature energization of the ringing control relay IIC. Thatwis, due to this` short dead period, although adischarge ot' ringing current may effect a momentary kick of the armature ot' relay CS, said relay armature .will again drop back before the lower winding of relay RC is connected to the live segment of the interrupter I.

In general. the ope 'ation of the system is as follows: The operator having .inserted the answering plug l into a jack J of a calling line, relay AS automatically connects the opertors telephone O to the calling line. After ascertaining the number of the want-v ed line, tht narrator tests in the usual manner by placa@L the tip of plug 2 against the jack J1 5- Fie called line. Assuming the line is idle .te calling plug Q is inserted into a jack J1 whereby the switching relay SW disconnects the operators telephone O and connects ground to the interrupter relay IR whereby it is periodically energized by the interrupter I to alternately bridge generator G and snpervisory relay CS across the called line. lVhen the subscriber responds relay CS energizes closingthe circuit of the lower winding of relay RC whereiiy upon thev following closure oli the control relay brush C of the interrupter I, relay .RC en? ergizes to Iclose the talking strands oit the link circuit. The operation of relays CS and RC also interrupts the circuit for relay IR thus preventing any further application of ringing`\ current. The answering and callingr supervisory lamps 5 and (i respectively are controlled'by the answering and calling supervisory relays in the usual Inanner. l

Referring now niore particularly to the operation of the system, in initiating a. call, a calling subscriber removes his receiver to operate his line relay LR and line lamp 7 whereby the operator inserts an answering plug 1 into the jack J of the calling'line thus energizing the cutoff relay C() and ei-v 'acing signal 7. The answering supervisory relay AS is thus connected in bridge of the calling line whereby` current iows through the winding thereof causing the energization thercotand the closing of its alternate contacts S, 9. Operators telephone O is thus connected by means of strands 10, 11, and through. normal contacts 12, 13 to the link circuit. '.lhc operator finding that connection is desired with another line tests said line to determine its idle or busy conr[dition by placing the tipzof the calling plug 40 9 vJack J1.

battery connection to saidline from the conagainst the test contact of the called line It said line is busy there will be a ne'cted plug but it' Isaid line is idle there is -no'such connection but instead ground p0- tential. lVith a battery cenncction a busy elicit is transmitted 1n a well-known manvner and it' idle,` no such signal is transmitted.v

. relays Ill and RC and calling supervisory signal Thus alternate contact lrhaving closed` upon the followingr closure 'et battery to lhc interruptor brush lt ot' interruptcr l. a circuit 'lor inlerrupter or ringing relay IR is established traced from battery through said brush R., normal contacts 16,

1T, and the winding of IR to ground at 'altrrnate contact l5. Relay IR therefore closes its alternate contacts 1S. 19, connecting generator G in bridge ot the called line to signal the call-bell at a substantion thereon. 'l`he continued rotation ot' interruptor ll?. causes an interruption ot the circuit of lll to bring about thel disconnection or' ring ingl current and the bridging of relay CS. 1 short dead period of interruptor I then ensues after which battery is connected to the control relay brush C but it the subscriber has not as yet responded the supervisory relay CS is still inert and therefore no disconnect circuit is provided. The continued operation of interruptor I thus alternately connects the ringing generator and thc calling supervisory relay in bridge ol the called line, but due to the condenser interposed in the called line circuit whileA the receiver is on the switch-hook, no path for direct current is provided for the relay CS. by the'removal of the receiver of hisvsubstation, and assuming that this occurs during a silent interval and while battery is connected to brush C, relay CS is energized by current flowing over the called line whereby its normal contact 20 is interrupted to c-iiace signal G. The interruption of normal contact 1G of CS prevents any further applications ot' ringing current and the` closing of alternate contact 2l provides an energizing circuit for ringing control relay il@ established from battery through brush alternate contact 21, and the lower windinl"r ot llC to ground at alternate contact l5. llpon cnergizat-ion of relay RC 'alternate contacts 22, 23. close thc tip and sleeve talking strands and the closing of alternate eentact 2+ establishes a locking circuit for RC through the upper winding thereof. The interruption ot` normal contact 17 of RC prevents a subsequent operation of the interrupter relay IR and the application of ringing current when the called Subscriber replaces his receiver and causes the restoration of CS. It will be apparent from the foregoing that the application of ringing current and disconnection thereof is controlled by alternately closed interrupter contacts. Assuming again that ringing eurrcnt is being applied to the called line as betore` but that a response is made Iinst before the battery scgnient of the interrupter I advanocs into engagement with the brush R that is withI Athe intcrrupter wheel I in a d `ad period.I In such case the removal of the receiver causes the encrgization of'CS as before, and upon the battery segment connecting with-brush R, interrupts.' relay llt would again energize to again cause the Upon response ot' the called subscriber restoration of (ls, if it was notfor the interruption ot the circuit of IR at normal contact 16 of CS. Therefore as the battery rac segment continues in its rotation and connects with the brush O, relay RG is energized as Ibefore locking itself and establishing the continuity of the talking conductors. After the subscribers havefinished conversation they will replace their receivers upon their respective switch-hooks to cause ,the restoration of the supervisory relays AS and CS. Responsive to the closing of normal contact of AS, signal 5 is lighted and upon the closing of normal contact 2O of CS signal 6 is lighted. The operator noting these signals will remove the connectingl plugs l and 2 from their respective spring jacks whereby relays AS and SlVare restored to nolinal. Upon the restoration of SIV the circuit for RC is interrupted causing its restoration, the interruption of alternate Contact l5 of SIN also ef facing' signals 5, 6. The apparatus is thus at normal and available for use in establishing other connections. vAgain assuming that calling plug :2 is in connection with the jack of `a called line and ringing currentis being applied as described, upon each restoration of relay I R a discharge of ringing current through the windings of relay CS is brought about causing said relay to momentarily kick up its armature at times. Such` incidental operation of relay OS does not cause the operation of ringing control relay RC because of the dead period on the interrupter wheel. That is when relay CS kicks up its armature,l although the alternate contact 2l thereof may be closed, circuit for RC-is not established because at this time the brush C is rresting upon the dead segment of the in 4rrupterwheel and' the armature of CS retits before the battery segment reachesgth .brush C.

It will be apparent trom the foregoing that althoughthe supervisory relay CS may have its armature kicked up incidentally, duc to.- the dead period of the interruptor, wheel the control circuits are not aiected.

Although I have embodied myfinvention', in simple OperatOrscOrd circliit, I coh'-,v template 'using it .i'n other ways. I am also aware 'hat changes and modifications thereofjwill occur to those skilled in the art and .I Iyaim to cover all such" changes and modifications/by the appendedclaims. i Having described my'invention, what I iclaim'as'i new and desire to secure by United 'Stites'L/etters Patent is:

A telephone system comprising teleyphone lines, a link circuiti'for connection therewith, afcalling supervisory relay and 'source or ringing current, an interrupter relay and means for operation thereofto'alter- `na't'ely `bridge said relay and current across a connected called line, a ringing control relay and energizing circuit therefor respon- "sive to said supervisory relay, an interrupter included in said energizing circuit, said interrupter being adapted to prevent a premature operation of said control relay by an incidental momentary operation of the supervisory relay.

2. A telephone system comprising telephone lines, a link circuit for connection therewith, a calling supervisory relay and source/of ringing current, means for alternately connecting said relay and current in bridge of a connected called line, a ringing control relay and energizing circuit therefor responsive to said supervisory relay, an interruptor included in the circuit of thecontrol relay, said interrupter being adapted to prevent a premature operation of the control relay by an incidental momentary operation of the supervisory relay.

3. A telephone system comprising telephone lines, an operator controlledlink circuit Jfor connection therewith, a calling supervisory relay and source of ringing current, means responsive to the connection of said link circuit to a' called one-of said lines for alternately connecting said relay and current in bridge oi a connected called line, a ringing control relay and energizing circuit therefor responsive to said supervisory relay, an interruptor included in the circuit 45A telephone system comprising telephone lin'es, an operators link circuit for connection' therewith, a ringing or interjtjupter relay a ringing control relay and a calling supervisory relay for said link circuit, an energizing circuit for each of said interrupter andcontrol relays, an interrupte'r-having alternate contacts included in said'circuits, means responsive to the connection of said link circuit to a called one of said lines whereby said circuit of the inter- -Y 'r'upter relay is'effective to periodically apply ringing current to said line, and means for energizing said supervisory relay upon response of the called line to establish said energizing circuit for the control relay to prevent urther application of ringing current.

5. A telephone system comprising Van operators link circuit, telephone lines adapted for connection therewith, an interrupter relay a ringing control relay and a calling supervisory relay for said link circuit, an interrupter having alternate contacts adapted -tobe alternately connected in energizing circuits for the ringing and interrupter relays, nieans responsiveto the connection ot said link circuit to one oi said lines whereby one of the alternate contacts of said interrupter causes the operation ot said'interrupter relay to periodically apply ringing currentto the connected line, means whereby 'said supervisory relay is energized upon resupervisory y rela-y.

sponSe from the connected line to close an' energizing circuit for the ringing control relay through the other alternate contact ot' the interrupter to prevent further application of ringing current to the connectedline.

6. A telephone system comprising telephone lines, a link circuit for connection therewith, interruptor, ringing control and calling supervisory relays for said link circuit, energizing circuits for said interrupter and control relays, an interrupt-er having alternate contacts one included in each of said circuits, means for causing the operation of said intcrrupter relay overits said circuit to periodically apply ringing current t o a connected called line, and means for energizing said supervisory relay upon response of the called line to establish said energizing circuit for the controlrelay to prevent further application of ringing current.

RICHARD I. UTTER.

Witnesses: A

GEORGE E. MUELLER, M. RL RocHroRD. 

